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Fuel economy and oil pressure, '94 Ford F-150


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06-14-04, 06:09 AM   #1  
Fuel economy and oil pressure, '94 Ford F-150

Need some input, please. I just acquired a 1994 Ford F-150 pickup, extended cab, 4.9l I-6, overdrive automatic trans, and dual fuel tanks. It's got around 105,000 miles on the odometer. Yesterday, I drove from Branson, Missouri to Hobbs, New Mexico, a total of 836 miles, and averaged 14.15 miles per gallon. I was thinking that with the 6 cylinder engine, it would get better mileage than that. Am I mistaken for thinking this, or should it get better mileage than that? Also, the oil pressure guage shows mostly on the low side of normal, but from time to time (with the engine running and warmed up) creeps up to the middle of the normal scale. Could I have a bad oil pressure sensor causing this? The truck seldom ran during the last two years, but I changed the oil and filter prior to the long drive. Any/all input is always appreciated. Thanks - Chris

 
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06-14-04, 09:14 PM   #2  
blsmith
No good news.

I have that same engine in a 91 E250 van. C6 transmission, no overdrive and 157K miles. I only get 9 miles to the gallon on the highway.

 
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06-15-04, 02:28 AM   #3  
Posted By: CMil Could I have a bad oil pressure sensor causing this?
You certainly could. That would be the first thing to address. You could go through the hassle of installing a manual gauge to determine accuracy but it would probably be easier to just replace the sender.
I have seen more than a couple of those particular trucks get sludged up inside and the sludge hardens and starts to flake off and land in the oil pan. From there it gets drawn into the oil pick up screen and intermittantly restricts oil flow. After dropping the pan and cleaning it out, then replacing the oil pump and pick up, I never had any more problems with them. These vehicles were much worse though. Thety were going all the way to zero pressure sometimes.

 
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06-15-04, 04:46 AM   #4  
Thanks, guys. yesterday, I replaced the spark plugs, air filter and sending unit and cleaned up the terminals on the distributor cap and rotor. Oil pressure is now in the middle of normal, and the truck starts and runs SO much better. I'll probably replace cap and rotor with new pieces before taking it back on the road, just to be sure, and see what the mileage does.
By the way, has anybody been told that American cars need to be run with American spark plugs and foreign cars with imported plugs? I was told (by a supposedly trained, competent mechanic) that it made a difference, that an Oldsmobile (for instance) would run better on AC spark plugs than on Bosch. Does this sound correct to anybody?
Again, thanks for the input. - Chris

 
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06-15-04, 02:20 PM   #5  
My opinion is use what the oe manufacturer specifies.The parts selected by them match the design characteristics of their vehicles.This is for maximum performance.

 
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06-15-04, 03:35 PM   #6  
Posted By: CMil By the way, has anybody been told that American cars need to be run with American spark plugs and foreign cars with imported plugs? I was told (by a supposedly trained, competent mechanic) that it made a difference, that an Oldsmobile (for instance) would run better on AC spark plugs than on Bosch. Does this sound correct to anybody?
Again, thanks for the input. - Chris
That is COMPLETELY true. I don't use Bosch in anything though. NGK in the imports.

 
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06-15-04, 07:55 PM   #7  
Wow! The spark plug thing really comes as a surprise! I quit using Motorcraft, Autolite and Mighty spark plugs ( and Champion in anything but my lawn equipment) because I've seen them just quit firing for no apparent reason, and have used Bosch Supers in everything I drive with reliable, satisfactory performance. I may have to change my thinking, though. What's the big factor in the difference between one plug and another? Is it internal resistance or something like that?

 
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06-16-04, 03:56 AM   #8  
It's hard to say just what it is but I assume the plug design is tailored to that ignition system. I've had exactly the opposite finding with Bosch plugs than yours. I've cured a lot of "problem childs" by removing them. Other techs have had the same experience.

 
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06-16-04, 02:26 PM   #9  
Good enough for me. Next time I change plugs, it's American brands in my American stuff. And if I ever buy another import, it'll be NGK's. Thanks again for all the advice. - Chris

 
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